31 research outputs found
Implementação do roteiro metodológico como experiência curricular universitária para o desenvolvimento de competências cooperativas
Objetivo. Evaluar la promoción de la competencia cooperativa en el contexto de la formación inicial docente desde la percepción del alumnado y del equipo de docentes. Metodología: Se diseñó desde un enfoque cualitativo y desde las tradiciones metodológicas de la investigación-acción en el aula y de la narrativa-biográfica, una propuesta curricular basada en el guion metodológico del espacio pedagógico de psicología del aprendizaje, como formato didáctico a implementar en el aula; desde una mirada evaluativa se analizaron tres fases: inicial, procesual y final. Los instrumentos empleados fueron un cuestionario cerrado, para evaluar las necesidades formativas del alumnado, el diario del investigador o investigadora para registrar las reflexiones del equipo docente y una entrevista semiestructurada aplicada a estudiantes. Las personas participantes fueron 47 estudiantes y el equipo docente estuvo integrado por 3 profesionales. Resultados. Los resultados indican que, para el alumnado, la experiencia formativa implementada favoreció la reconstrucción de significados, experiencias y comprensiones sobre el trabajo cooperativo en el contexto de la profesión y, desde la percepción del personal docente permitió nuevos espacios de reflexión e integración de la teoría y la práctica. Conclusión. La experiencia curricular implementada en un contexto dialógico y cooperativo permitió comprender que la competencia cooperativa, no es un fin en sí misma, sino que favorece la construcción de la identidad docente.Aim. Cooperative competence is considered a key in the teaching profession, which is why this work evaluated its promotion from the perception of students and teachers in the context of initial training. Method. For this, a curricular proposal was designed from the action research perspective in the classroom, from the methodological script of the pedagogical space of learning psychology, and from an evaluative perspective analyzing initial, procedural, and final phases. The instruments used were a closed questionnaire to assess the students’ training needs, a researcher’s journal to record the reflections of the teaching team, and a semi-structured interview applied to students. The participants were 47 students 3 teachers. Results. The results indicate that, for the students, the training experience implemented favored the reconstruction of meanings, experiences, and understandings of cooperative work in the context of the profession and, from the teachers’ perception, allowed new spaces for reflection and integration of the theory and practice. Conclusion. The curricular experience implemented in a dialogical and cooperative context allowed understanding that cooperative competence is not an end in itself but rather favors the construction of teaching identity.Objetivo. Avaliar a promoção da competência cooperativa no contexto da formação inicial a partir da percepção dos estudantes e da equipe docente. Metodologia. Para tanto, delineouse uma proposta curricular e enfoque qualitativo, a partir da investigação-ação na sala de aula e da narrativa biográfica, a partir do roteiro metodológico do espaço pedagógico da psicologia da aprendizagem e, sob uma perspectiva avaliativa, foram analisadas três fases: inicial, processual e final. Os instrumentos utilizados foram um questionário fechado, para avaliar as necessidades formativas do grupo de estudantes, o diário do pesquisador para registrar as reflexões da equipe de docentes e uma entrevista semiestruturada aplicada aos estudantes. Participaram 47 estudantes e a equipe docente era composta por 3 profissionais. Resultados. Os resultados indicam que, para o grupo de estudantes, a experiência de formação implementada favoreceu a reconstrução de significados, experiências e entendimentos sobre o trabalho cooperativo no contexto da profissão e, a partir da percepção da equipe docente, permitiu novos espaços de reflexão e integração da teoria e da prática. Conclusão. A experiência curricular implementada em um contexto dialógico e cooperativo nos permitiu entender que a competência cooperativa não é um fim em si mesma, mas favorece a construção da identidade docente
Determining the impact of uncharacterized inversions in the human genome by droplet digital PCR
Despite the interest in characterizing genomic variation, the presence of large repeats at the breakpoints hinders the analysis of many structural variants. This is especially problematic for inversions, since there is typically no gain or loss of DNA. Here, we tested novel linkage-based droplet digital PCR (ddPCR) assays to study 20 inversions ranging from 3.1 to 742 kb flanked by inverted repeats (IRs) up to 134 kb long. Of those, we validated 13 inversions predicted by different genome-wide techniques. In addition, we obtained new experimental human population information across 95 African, European, and East Asian individuals for 16 inversions, including four already validated variants without high-throughput genotyping methods. Through comparison with previous data, independent replicates and both inversion breakpoints, we demonstrate that the technique is highly accurate and reproducible. Most studied inversions are widespread across continents, and their frequency is negatively correlated with genetic length. Moreover, all except two show clear signs of being recurrent, and we could better define the factors affecting recurrence levels and estimate the inversion rate across the genome. Finally, the generated genotypes have allowed us to check inversion functional effects, validating gene expression differences reported before for two inversions and finding new candidate associations. Therefore, the developed methodology makes it possible to screen these and other complex genomic variants quickly in a large number of samples for the first time, highlighting the importance of direct genotyping to assess their potential consequences and clinical implications
Global network of computational biology communities: ISCB's regional student groups breaking barriers [version 1; peer review: Not peer reviewed]
Regional Student Groups (RSGs) of the International Society for Computational Biology Student Council (ISCB-SC) have been instrumental to connect computational biologists globally and to create more awareness about bioinformatics education. This article highlights the initiatives carried out by the RSGs both nationally and internationally to strengthen the present and future of the bioinformatics community. Moreover, we discuss the future directions the organization will take and the challenges to advance further in the ISCB-SC main mission: “Nurture the new generation of computational biologists”.Fil: Shome, Sayane. University of Iowa; Estados UnidosFil: Parra, Rodrigo Gonzalo. European Molecular Biology Laboratory; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fatima, Nazeefa. Uppsala Universitet; SueciaFil: Monzon, Alexander Miguel. Università di Padova; ItaliaFil: Cuypers, Bart. Universiteit Antwerp; BélgicaFil: Moosa, Yumna. University of KwaZulu Natal; SudáfricaFil: Da Rocha Coimbra, Nilson. Universidade Federal de Minas Gerais; BrasilFil: Assis, Juliana. Universidade Federal de Minas Gerais; BrasilFil: Giner Delgado, Carla. Universitat Autònoma de Barcelona; EspañaFil: Dönertaş, Handan Melike. European Molecular Biology Laboratory. European Bioinformatics Institute; Reino UnidoFil: Cuesta Astroz, Yesid. Universidad de Antioquia; Colombia. Universidad Ces. Facultad de Medicina.; ColombiaFil: Saarunya, Geetha. University of South Carolina; Estados UnidosFil: Allali, Imane. Universite Mohammed V. Rabat; Otros paises de África. University of Cape Town; SudáfricaFil: Gupta, Shruti. Jawaharlal Nehru University; IndiaFil: Srivastava, Ambuj. Indian Institute of Technology Madras; IndiaFil: Kalsan, Manisha. Jawaharlal Nehru University; IndiaFil: Valdivia, Catalina. Universidad Andrés Bello; ChileFil: Olguín Orellana, Gabriel José. Universidad de Talca; ChileFil: Papadimitriou, Sofia. Vrije Unviversiteit Brussel; Bélgica. Université Libre de Bruxelles; BélgicaFil: Parisi, Daniele. Katholikie Universiteit Leuven; BélgicaFil: Kristensen, Nikolaj Pagh. Technical University of Denmark; DinamarcaFil: Rib, Leonor. Universidad de Copenhagen; DinamarcaFil: Guebila, Marouen Ben. University of Luxembourg; LuxemburgoFil: Bauer, Eugen. University of Luxembourg; LuxemburgoFil: Zaffaroni, Gaia. University of Luxembourg; LuxemburgoFil: Bekkar, Amel. Universite de Lausanne; SuizaFil: Ashano, Efejiro. APIN Public Health Initiatives; NigeriaFil: Paladin, Lisanna. Università di Padova; ItaliaFil: Necci, Marco. Università di Padova; ItaliaFil: Moreyra, Nicolás Nahuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin
Functional impact and evolution of a novel human polymorphic inversion that disrupts a gene and creates a fusion transcript
Since the discovery of chromosomal inversions almost 100 years ago, how they are maintained in natural populations has been a highly debated issue. One of the hypotheses is that inversion breakpoints could affect genes and modify gene expression levels, although evidence of this came only from laboratory mutants. In humans, a few inversions have been shown to associate with expression differences, but in all cases the molecular causes have remained elusive. Here, we have carried out a complete characterization of a new human polymorphic inversion and determined that it is specific to East Asian populations. In addition, we demonstrate that it disrupts the ZNF257 gene and, through the translocation of the first exon and regulatory sequences, creates a previously nonexistent fusion transcript, which together are associated to expression changes in several other genes. Finally, we investigate the potential evolutionary and phenotypic consequences of the inversion, and suggest that it is probably deleterious. This is therefore the first example of a natural polymorphic inversion that has position effects and creates a new chimeric gene, contributing to answer an old question in evolutionary biology
Large-scale evolutionary analysis of polymorphic inversions in the human genome
Les inversions cromosòmiques són variants estructurals on un fragment de genoma s'inverteix sense canviar-ne el contingut, i durant anys, els seus efectes subtils però importants han fascinat els biòlegs evolutius. De fet, les inversions van ser descobertes per primer cop fa cent anys en mosques de la fruita, i aviat es va fer evident la seva associació a processos evolutius com l'adaptació local i l'especiació. Tot i així, en el moment en què vivim de la genòmica i el big data, les inversions tendeixen a quedar fora de l'abast de les tecnologies més comunes i encara se sap poc d'elles. Durant els últims anys, el Projecte InvFEST ha tingut com a objectiu ampliar el nostre coneixement sobre les inversions humanes mitjançant la validació i genotipació d'una gran part de les inversions predites. En concret, aquest projecte ha generat un recurs molt útil format per 45 inversions comunes (d'entre 83 pb i 415 kpb) amb genotips d'alta qualitat per a un total de 550 individus de set poblacions diverses. En aquesta tesi s'utilitzen les dades poblacionals generades, junt amb les seqüències del Projecte 1000 Genomes, per a realitzar la primera anàlisi detallada de les propietats evolutives de les inversions polimòrfiques humanes. Per aconseguir-ho, s'han fet servir diferents mètodes que combinen models teòrics, simulacions i comparacions amb altres tipus de mutacions. A part d'obtenir una caracterització completa de les dades, els resultats confirmen que hi ha diferències importants entre inversions generades per diferents mecanismes. La distribució de freqüències de les 21 inversions creades per mecanismes no homòlegs (NH) és semblant a l'esperada per a variants neutres si es controlen els biaixos en la detecció, indicant que no es troben sota una forta selecció negativa. La recombinació s'inhibeix en tota la longitud de la inversió, sense que s'observi cap intercanvi de variants entre orientacions, i la inhibició podria estendre's alguna kilobase més enllà dels punts de trencament. Com a resultat, els nivells de variació genòmica es veuen força afectats per les inversions NH, tal i com prediuen les simulacions realitzades. Mentre que les inversions antigues i a freqüències intermèdies augmenten la variació nucleotídica, les inversions més recents poden crear l'efecte contrari. En canvi, la majoria de les inversions creades per recombinació homòloga no al·lèlica (NAHR) (19/24) han aparegut múltiples vegades de manera independent en diferents haplotips de la mostra. Els elevats nivells de recurrència es reflecteixen en diferents mesures: aquestes inversions estan enriquides en freqüències intermèdies, comparteixen polimorfismes nucleotídics entre orientacions, i es troben en baix desequilibri de lligament amb variants properes, dificultant-ne la seva detecció indirecta amb variants correlacionades. Finalment, per tal de trobar aquelles inversions candidates a tenir efectes funcionals, s'han explorat diverses senyals de selecció natural a partir de freqüències, diferenciació poblacional i patrons de variació nucleotídica. S'han identificat deu inversions candidates, tres d'elles de més de 1.5 milions d'anys i mantingudes a freqüències intermèdies, possiblement per selecció equilibradora, una d'elles també es troba a genomes d'hominins antics. Altres candidates sembla que han augmentat ràpidament de freqüència en algunes poblacions, que és consistent amb selecció positiva. Cal destacar que més de la meitat de candidates estan situades en regions gèniques, el qual suggereix que poden tenir un efecte funcional. Per tant, aquest treball ofereix una visió global de la dinàmica de les inversions i el seu paper com modificadors genòmics, obrint noves línies d'investigació.Chromosomal inversions are structural variants that invert a fragment of the genome without usually modifying its content, and their subtle but powerful effects in natural populations have fascinated evolutionary biologists for a long time. Discovered a century ago in fruit flies, their association with different evolutionary processes, such as local adaptation and speciation, was soon evident in several species. However, in the current era of genomics and big data, inversions frequently escape the grasp of current technologies and remain largely overlooked in humans. During the last few years, the InvFEST Project has aimed to address the missing knowledge about human inversions by validating and genotyping a large fraction of predicted polymorphisms. In particular, it has generated one of the most useful data sets on human inversions, consisting of 45 common inversions (with sizes from 83 bp to 415 kbp) genotyped at high-quality in 550 individuals of seven populations of diverse ancestry. This thesis takes advantage of the available population-scale information, combined with whole-genome sequences available from the 1000 Genomes Project, to carry out the first detailed analysis of the evolutionary properties of human polymorphic inversions. The methods used combine theoretical models, simulations and empirical comparisons with other mutation types. Besides the complete characterization of the data set, the results confirm fundamental differences between inversions created by different mechanisms. The frequency distribution of the 21 inversions originated by non-homologous mechanisms (NH) is similar to that expected for neutral variants when controlling for detection biases, which indicates that they are not subjected to strong negative selection. Recombination is completely inhibited across the whole inversion length, with no clear genetic exchange found, and possibly over a few kbp beyond the breakpoints. As a result, NH inversions strongly affect local genome variation levels, as predicted by computer simulations, with older inversions increasing total nucleotide diversity, while younger ones at very high frequency could have the opposite effect. In contrast, most inversions created by non-allelic homologous recombination (NAHR) (19/24) have appeared independently in different haplotypes in the sample. These high recurrence levels are reflected in several measures: they are enriched in intermediate frequencies, share multiple nucleotide polymorphisms between orientations, and have little linkage disequilibrium with neighbouring variants, which limits their detection by tag SNP strategies. Finally, in order to find inversions that are functional candidates, different signatures of selection on inversions were explored based on their frequencies, population differentiation and sequence variation patterns. Ten candidates were revealed, with three of them found to be >1.5 million years old and maintained at intermediate frequencies, possibly by balancing selection. One of these was also found in archaic hominins. Other candidates seem to have reached high frequencies in a short period of time in some populations, consistent with positive selection. Notably, over half of the candidates are located within gene regions, which suggests that they may have functional effects. Thus, this work offers an overview of inversion dynamics and their role as genomic modifiers, opening interesting avenues of investigation
Large-scale evolutionary analysis of polymorphic inversions in the human genome /
Bibliografia.Premi Extraordinari de Doctorat concedit pels programes de doctorat de la UAB per curs acadèmic 2017-2018Les inversions cromosòmiques són variants estructurals on un fragment de genoma s'inverteix sense canviar-ne el contingut, i durant anys, els seus efectes subtils però importants han fascinat els biòlegs evolutius. De fet, les inversions van ser descobertes per primer cop fa cent anys en mosques de la fruita, i aviat es va fer evident la seva associació a processos evolutius com l'adaptació local i l'especiació. Tot i així, en el moment en què vivim de la genòmica i el big data, les inversions tendeixen a quedar fora de l'abast de les tecnologies més comunes i encara se sap poc d'elles. Durant els últims anys, el Projecte InvFEST ha tingut com a objectiu ampliar el nostre coneixement sobre les inversions humanes mitjançant la validació i genotipació d'una gran part de les inversions predites. En concret, aquest projecte ha generat un recurs molt útil format per 45 inversions comunes (d'entre 83 pb i 415 kpb) amb genotips d'alta qualitat per a un total de 550 individus de set poblacions diverses. En aquesta tesi s'utilitzen les dades poblacionals generades, junt amb les seqüències del Projecte 1000 Genomes, per a realitzar la primera anàlisi detallada de les propietats evolutives de les inversions polimòrfiques humanes. Per aconseguir-ho, s'han fet servir diferents mètodes que combinen models teòrics, simulacions i comparacions amb altres tipus de mutacions. A part d'obtenir una caracterització completa de les dades, els resultats confirmen que hi ha diferències importants entre inversions generades per diferents mecanismes. La distribució de freqüències de les 21 inversions creades per mecanismes no homòlegs (NH) és semblant a l'esperada per a variants neutres si es controlen els biaixos en la detecció, indicant que no es troben sota una forta selecció negativa. La recombinació s'inhibeix en tota la longitud de la inversió, sense que s'observi cap intercanvi de variants entre orientacions, i la inhibició podria estendre's alguna kilobase més enllà dels punts de trencament. Com a resultat, els nivells de variació genòmica es veuen força afectats per les inversions NH, tal i com prediuen les simulacions realitzades. Mentre que les inversions antigues i a freqüències intermèdies augmenten la variació nucleotídica, les inversions més recents poden crear l'efecte contrari. En canvi, la majoria de les inversions creades per recombinació homòloga no al·lèlica (NAHR) (19/24) han aparegut múltiples vegades de manera independent en diferents haplotips de la mostra. Els elevats nivells de recurrència es reflecteixen en diferents mesures: aquestes inversions estan enriquides en freqüències intermèdies, comparteixen polimorfismes nucleotídics entre orientacions, i es troben en baix desequilibri de lligament amb variants properes, dificultant-ne la seva detecció indirecta amb variants correlacionades. Finalment, per tal de trobar aquelles inversions candidates a tenir efectes funcionals, s'han explorat diverses senyals de selecció natural a partir de freqüències, diferenciació poblacional i patrons de variació nucleotídica. S'han identificat deu inversions candidates, tres d'elles de més de 1.5 milions d'anys i mantingudes a freqüències intermèdies, possiblement per selecció equilibradora, una d'elles també es troba a genomes d'hominins antics. Altres candidates sembla que han augmentat ràpidament de freqüència en algunes poblacions, que és consistent amb selecció positiva. Cal destacar que més de la meitat de candidates estan situades en regions gèniques, el qual suggereix que poden tenir un efecte funcional. Per tant, aquest treball ofereix una visió global de la dinàmica de les inversions i el seu paper com modificadors genòmics, obrint noves línies d'investigaci
Determining the impact of uncharacterized inversions in the human genome by droplet digital PCR
Despite the interest in characterizing genomic variation, the presence of large repeats at the breakpoints hinders the analysis of many structural variants. This is especially problematic for inversions, since there is typically no gain or loss of DNA. Here, we tested novel linkage-based droplet digital PCR (ddPCR) assays to study 20 inversions ranging from 3.1 to 742 kb flanked by inverted repeats (IRs) up to 134 kb long. Of those, we validated 13 inversions predicted by different genome-wide techniques. In addition, we obtained new experimental human population information across 95 African, European, and East Asian individuals for 16 inversions, including four already validated variants without high-throughput genotyping methods. Through comparison with previous data, independent replicates and both inversion breakpoints, we demonstrate that the technique is highly accurate and reproducible. Most studied inversions are widespread across continents, and their frequency is negatively correlated with genetic length. Moreover, all except two show clear signs of being recurrent, and we could better define the factors affecting recurrence levels and estimate the inversion rate across the genome. Finally, the generated genotypes have allowed us to check inversion functional effects, validating gene expression differences reported before for two inversions and finding new candidate associations. Therefore, the developed methodology makes it possible to screen these and other complex genomic variants quickly in a large number of samples for the first time, highlighting the importance of direct genotyping to assess their potential consequences and clinical implications
Functional impact and evolution of a novel human polymorphic inversion that disrupts a gene and creates a fusion transcript
Altres ajuts: a PIF PhD fellowship from the Universitat Autònoma de Barcelona (Spain) to CGD, and a Beatriu de Pinós Postdoctoral fellowship by the Commission for Universities and Research of the Ministry of Innovation, Universities and Enterprise of the Autonomous Government of Catalonia and the Cofund programme of the Marie Curie Actions of the FP7 to JILL.Despite many years of study into inversions, very little is known about their functional consequences, especially in humans. A common hypothesis is that the selective value of inversions stems in part from their effects on nearby genes, although evidence of this in natural populations is almost nonexistent. Here we present a global analysis of a new 415-kb polymorphic inversion that is among the longest ones found in humans and is the first with clear position effects. This inversion is located in chromosome 19 and has been generated by non-homologous end joining between blocks of transposable elements with low identity. PCR genotyping in 541 individuals from eight different human populations allowed the detection of tag SNPs and inversion genotyping in multiple populations worldwide, showing that the inverted allele is mainly found in East Asia with an average frequency of 4.7%. Interestingly, one of the breakpoints disrupts the transcription factor gene ZNF257, causing a significant reduction in the total expression level of this gene in lymphoblastoid cell lines. RNA-Seq analysis of the effects of this expression change in standard homozygotes and inversion heterozygotes revealed distinct expression patterns that were validated by quantitative RT-PCR. Moreover, we have found a new fusion transcript that is generated exclusively from inverted chromosomes around one of the breakpoints. Finally, by the analysis of the associated nucleotide variation, we have estimated that the inversion was generated ~40,000-50,000 years ago and, while a neutral evolution cannot be ruled out, its current frequencies are more consistent with those expected for a deleterious variant, although no significant association with phenotypic traits has been found so far
Validation and Genotyping of Multiple Human Polymorphic Inversions Mediated by Inverted Repeats Reveals a High Degree of Recurrence
In recent years different types of structural variants (SVs) have been discovered in the human genome and their functional impact has become increasingly clear. Inversions, however, are poorly characterized and more difficult to study, especially those mediated by inverted repeats or segmental duplications. Here, we describe the results of a simple and fast inverse PCR (iPCR) protocol for high-throughput genotyping of a wide variety of inversions using a small amount of DNA. In particular, we analyzed 22 inversions predicted in humans ranging from 5.1 kb to 226 kb and mediated by inverted repeat sequences of 1.6-24 kb. First, we validated 17 of the 22 inversions in a panel of nine HapMap individuals from different populations, and we genotyped them in 68 additional individuals of European origin, with correct genetic transmission in ∼12 mother-father-child trios. Global inversion minor allele frequency varied between 1% and 49% and inversion genotypes were consistent with Hardy-Weinberg equilibrium. By analyzing the nucleotide variation and the haplotypes in these regions, we found that only four inversions have linked tag-SNPs and that in many cases there are multiple shared SNPs between standard and inverted chromosomes, suggesting an unexpected high degree of inversion recurrence during human evolution. iPCR was also used to check 16 of these inversions in four chimpanzees and two gorillas, and 10 showed both orientations either within or between species, providing additional support for their multiple origin. Finally, we have identified several inversions that include genes in the inverted or breakpoint regions, and at least one disrupts a potential coding gene. Thus, these results represent a significant advance in our understanding of inversion polymorphism in human populations and challenge the common view of a single origin of inversions, with important implications for inversion analysis in SNP-based studies